This invention relates to a punch press of the type in which a vertically reciprocable punch coacts with an underlying die to form a hole in an intervening workpiece. A stripper usually encircles the punch and holds the workpiece downwardly against the die when the punch is retracted in order to prevent the workpiece from being lifted upwardly by the punch.
The invention more particularly relates to a punch press of the tool changing type in which the punch, the stripper and the die are adapted to be removed automatically from their respective holders and replaced with another set of tools of a different size or shape. Tool changing presses have been marketed previously by Trumpf & Co. and include a magazine which holds several sets of vertically alined punches, strippers and dies. The magazine is indexed to bring a given set of tools to a tool changing station and then the tools are transferred from the magazine to the various holders. When the punching operation has been completed, the tools are transferred from the holders to the magazine preparatory to the magazine being indexed to bring a different set of tools to the tool changing station.
The press of the present invention preferably is equipped with a metal melting tool such as a plasma-arc torch of the type disclosed in Brolund et al U.S. Pat. No. 4,063,059. The torch is used to cut large and irregularly shaped openings in the workpiece and usually operates while the punch is inactive.